The "Night Stalker" refers to Richard Ramirez, an American serial killer and rapist who terrorized Southern California in the mid-1980s. He was linked to at least 13 murders, along with numerous sexual assaults and burglaries. His crimes were characterized by their brutality and randomness, leading to widespread fear in the communities he targeted. Ramirez was eventually captured in 1985 after a group of citizens recognized him from a police sketch. He was convicted in 1989 and sentenced to death. His case has been the subject of numerous documentaries and books, highlighting the impact of his crimes on victims and society.